A whole lot of futile speculation and educated (as well as not so educated) GUESSING about what Canon will end up doing to the 6D2 vs. its predecessor, and how the 6d2 will and won't be better/different from products which Canon visualizes as 'higher' in the product family. Having spent a lifetime in product management and planning, and with business school principles of said in my brain, I can say the below chart represents how Canon might conceptualize its family placement...but WHICH individual CHARACTERISTICS that go into the differentiation can vary at different levels, and at different times.
So it is possible that
- 'more pixels' equates to 'better IQ' in Canon's mind for 6D2 vs. 6D, and
- that 'better DR' might (in Canon's mind)already be in the 6D (vs. 80D and 5DIV) (putting it way ahead in time over its later brothers), so even more DR might not yet make sense
- they already know now the 6D high DR ate into 5Dn and 1Dn profits with the 6D superior noise that was not equalled until the 5DIV and 80D were launched with their new DR, and know not to repeat that profit erosion again
- the 7DIII might be improved in noise resistance and in pixel count to be similar to the 6DII, and
- the smaller sensor of the 7DIII might be viewed as sufficient differentiation to make it 'inferior' in position to the 6DII even with same pixel count and noise qualitiies as the 6DII,
- Yet the prosumer 7DIII might have better AF than the 6DII, and have 4K video too.
The possibilities are endless, and the subject of endless speculation...we can only wait to see what comes out, and when. And more is pointless and futile argument, ended when Canon makes its launches, and the newer (future) models are rumored and pointlessly (but wishfully) speculated about again.
My chart -- which shows nothing about price nor any of multiple performance axes -- above illustrates principles in product positioning, which might represent the 'ideal' for 2018, and which was inadvertantly violated by marketing positioning errors ("the 'pro feature set' of the 5Dn outweighs DR advantage of the 6D for pros") of 2014-2016 leading to profit erosion for Canon.